A method of transmitting and receiving a PSFCH in a wireless communication system and a device therefor are disclosed. The method performed by a first UE comprises receiving, from a second UE, a first PSCCH including first SCI, receiving, from a third UE, a second PSCCH including second SCI, determining, based on a resource reserved by the first SCI overlapping a resource reserved by the second SCI, a resource conflict in the resource reserved by the first SCI using a RSRP measured based on the first PSCCH and a RSRP measured based on the second PSCCH, and transmitting, to the second UE, the PSFCH including conflict information indicating the resource conflict in the resource.